The Obama administration is hailing the agreement between Afghanistan’s rival presidential candidates on forming a government of national unity, saying it marks an ‘important opportunity’ for unity and increased stability.

The agreement, ending a six-month political impasse, is the culmination of a power-sharing structure brokered by U.S. Secretary of State John Kerry, who said it ensures the first peaceful, democratic transition in Afghanistan.

The White House applauded former Afghan Foreign Minister Abdullah Abdullah and former Finance Minister and World Bank official Ashraf Ghani for signing the agreement, saying it “helps bring closure to Afghanistan’s political crisis, and restores confidence in the way forward.”

The statement said the United States supports the agreement and stands ready to work with the new administration to ensure its success.

President Barack Obama spoke with both men by telephone Sunday to congratulate them for their leadership and willingness to partner to advance Afghanistan's national interests.

Speaking at U.N. headquarters Sunday, Kerry reaffirmed America’s strategic partnership with Afghanistan and commitment to continue U.S. support of the new government.

"I want to congratulate Dr. Ashraf Ghani, the new president announced of Afghanistan, and Dr. Abdullah Abdullah for their joint act of statesmanship, for their leadership, for their willingness to put Afghanistan and the interests of the Afghan people ahead of their personal interests and party," Kerry said.

"They have joined together in a unity government that offers a huge opportunity for progress in Afghanistan and the signing of the BSA (Bilateral Security Agreement) in a week or so and the inauguration next week of the new president and, importantly, for a real program of unity and reform to be implemented on behalf of the people of Afghanistan," he added.

Mediated agreement

Kerry, who helped mediate the power-sharing agreement in August, said these developments will open a new chapter in U.S.-Afghan relations.

According to the four-page agreement, Ghani, who is expected to be sworn in September 29, will share power with Abdullah, who will be named chief executive. The two will share control over who leads key ministries.

"Afghanistan has traditionally had a decentralized system of governance. This agreement that soon-to-be-president Ghani and Abdullah Abdullah have put in place brings some of that local accountability and some of that deal-making that is so much part of Afghan politics back into the system," Blank said.

He added that he believes this agreement will defuse ethnic tensions in the country.

"If one candidate had simply been the winner-take-all champion and the other candidate had been left completely out in the cold, then a lot of the ethnic groups in Afghanistan, and it’s not just Pashtun versus Tajik, it’s also about the divisions within the Pashtun community, indeed within all the communities," Blank said.

"This arrangement lets all of those divisions and all of those conflicts get played out in the realm of politics rather than the realm of violence," he said.

Blank also praised what he called the statesmanship and patriotism of both Abdullah and Ghani for forging an agreement that he describes as not ideal from either perspective, but correct for the Afghan people.

Worrisome aspects

However, Nazif Shahrani, an Afghan-born Indiana University professor, said there are worrisome aspects to the agreement.

"It is essentially disrespecting people’s votes," Shahrani said. "The people, with all their enthusiasm six months ago went to the polls and voted, and again they did it in the second round, and both of [the elections] were basically fraudulent because of what the government, and those running [the election] and those who were administering it did. ...

"And, at the end, they did not even announce the percentages of the vote supposedly won or lost after six months and after huge costs to American taxpayers but, at the end, it was meaningless," Shahrani said. "It was a deal made between groups of elites, who are already in the government, who have been part of this government for the past 13 years."

He is concerned the two candidates will continue showing the mistrust in government they exhibited during the election process.

"If they trusted each other, [the election process] should not have gone this far. You remember, Secretary Kerry went twice to Kabul to broker this deal, and that did not work and, eventually, the deputy Secretary-General of the United Nations intervened, and the permanent representative there, and the U.S. ambassador there, Ambassador Cunningham," Shahrani said.

"Who ends up in the so-called unity government is still a puzzle. How are they going to be named, and who will name them, and how will they divvy up so-called key ministries and less important ministries? All of these are issues that could cause a great deal of concern," he added.

Shahrani said a positive outcome of this process is the winner-take-all presidency enshrined in the country’s constitution has been challenged. He called the power-sharing agreement a temporary solution, but hopes a Loya Jirga (grand council) scheduled in two years will address what he calls the constitutional concentration of power in the presidency.

Both analysts acknowledged the new leadership faces monumental economic, security and political challenges.